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CHAPTER II ALTERNATIVES, INCLUDING THE PROPOSED ACTION being used (e.g., by providing fish passage structures); ' reintroducing eggs or larvae into unoccupied spawning habitat; modifying instream characteristics to create new spawning habitat; or constructing spawning habitat within the natural stream channel or in ' modified side channels. Adult squawfish over-winter in runs and embayments. It may be possible to simulate this habitat by building jetties. But, because jetties may also enhance habitat for nonnative predatory fish or reduce shallow ephemeral areas, they should not be constructed in areas that might be occupied by young squawfish subject to predation, ' or in spawning areas. Dams have blocked historic migration routes for squawfish, reducing habitat availability. Locations under consideration for constructing fish passage facilities are Redlands, Taylor Draw, or other dams to reestablish Colorado squawfish in parts of their historic range now unoccupied. 3. Stocking of rare fish species. Artificial propagation could provide a means to avoid extinction and enhance populations for recovery purposes. Research will be conducted using hatchery-reared fish. Studies will range from basic species research (e.g., migration behavior, imprinting/homing, spawning, and interaction with wild populations) to fish culture research (e.g., appropriate hatchery ' loading densities, water requirements, and feeding rates). If results show that disease-free, genetically viable, hatchery-reared fish will survive and reproduce successfully in the wild, a hatchery production program may be used to augment stocks so that self- sustaining populations can become established. Grow-out ponds could be used as rearing areas for fry and young-of- year fishes. Grow-out ponds in Grand Junction, Colorado have produced Colorado squawfish in 1 year to a size that takes 3 years in the wild. Existing hatchery facilities will be evaluated to determine if they can produce enough genetically acceptable, disease-free fish for the research program. If necessary, additional capability could be provided through the modification of existing hatcheries or through grow-out ponds. Hatcheries will also be used as refugia for the rare fishes, with emphasis placed on maintaining genetically diverse and viable stock. If hatchery-reared fish survive and reproduce in the wild, a hatchery production program should be implemented to augment wild populations. Additional hatcheries could be necessary. Due to its precarious status in the Upper Basin, the bonytail chub will be reintroduced ' immediately. Where it would benefit existing wild populations, consideration will be given to supplementing existing populations of the other three fishes after sufficient research was completed. 1 II-7